1. Field of the Invention
The present invention relates to a grinding machine having arrangements for effecting truing and dressing of a grinding wheel made of hard material such as cubic boron nitride.
2. Description of the Prior Art
There has been known a grinding machine having a device for truing and dressing a so-called "CBN grinding wheel" in which cubic boron nitride abrasive grains are bonded on a circumferential surface of a metallic disc in the form of a stratum. Generally, such a truing and dressing device is composed of a truing wheel for truing the CBN grinding wheel, a dressing roll for backing up free abrasive grains acting as dressing agent, and a drive motor for rotating the truing wheel and the dressing roll and is disposed, as a solely completed device, either upon a work table or upon a wheel head. Therefore, there remains unsolved a problem in the respect that the cost of a grinding machine with such a complete truing and dressing device is increased.